When San Francisco-based artist Steve MacDonald first heard from a friend that his poster design for 2009 Bicycle Film Festival looked suspiciously like a Target body pillow cover, he was intrigued.

Then he was outraged.

After going to Target and purchasing the offending body pillow cover, he wrote a blog post titled, “Target Ripped Off My Art!” Reached over the phone, MacDonald elaborated upon the alleged copyright infringement.

“The thing that’s so similar is that they used the off-gray, off-greens [that I used]. It’s pretty rare to see those colors, so for them to have used the same color palette…” MacDonald trailed off. “The types of bikes that they chose, too…I’ve never seen anyone use a tall bike in an art piece.”

Plus, McDonald said, the poster was widely circulated, because the Bicycle Film Festival travels around the world. He also designed T-shirts and variations on the original item in different colors, with the same motif of the hand-drawn bikes.

Target, for its part, said that it takes such complaints very seriously. It advised MacDonald to send an e-mail.

The two designs do share basic similarities — primary colors, hand-drawn bikes, white background. Take a look MacDonald's poster (image is cropped), with a shot of the Target sheets underneath. (You can see more images from both pieces in our slideshow below.

But the similarities might not be enough to prove legal infringement. Simon Frankel, an SF attorney who specializes in copyright issues, would not comment on the merits of this situation specifically, but did offer a general perspective on the legalities of intellectual property.

“Generally, to prove copyright infringement, you have to show that the defendant had access to the original material and also show that the works are ‘substantially similar’ — that [the work] expresses something that is unique and special,” he said in a phone interview.

Frankel pointed out that even if a defendant in a copyright case had access to the prosecution’s source material and copied it, that isn’t enough to prove infringement — the image itself has to be singular enough to warrant protection.

“Applied here, a series of drawings of a bicycle does not necessarily infringe upon another drawing of a bicycle.”

MacDonald, pleading poverty, isn’t seriously considering legal recourse. He did want to voice his complaint, though, to Target and felt stymied by their website. He left a comment, to no avail. The whole thing felt especially ironic to him because of the style of the Target product. "It looks like they changed those bikes to be more handmade and organic," he said, "My stuff is all sewn onto fabric. To see it silkscreened onto a fabric piece, I don't know."

Here are the contested designs: What do you think?

Check out more shots of MacDonald's work and the Target brand sheets and images from some famous copyright infringement cases, in our slideshow: